Microscopic Description -- Osteolytic Lesion

MICROSCOPIC DESCRIPTION:

The bone contains a metaphyseal based neoplasm composed of
pleomorphic and hyperchromatic spindled to polygonal cells
in a mixed vascular and hyalinized stroma with focal osteoid formation.
Tumor giant cells are conspicuous. Mitoses average 1/HPF.
There is focal periosteal invasion.